Accompanying the popularization of cell phones, notebook personal computers, and other small electronic devices has been a great demand to reduce the size and thickness of the semiconductor devices carried in them. Together with BGA (Ball Grid Array) packages and SON (Small Outline Non-leaded) packages, QFN (Quad Flat No lead) packages have become a popular configuration for small integrated circuit (“IC”) packages with leadframes.
In QFN package formation, a leadframe strip containing multiple connected leadframes has multiple semiconductor dies mounted on it. This assembly is sealed with mold compound resins. The sealed assembly is diced (singulated) to form individual QFN packages. During dicing, a saw with a rotating blade, is moved along preset cutting lines across the sealed assembly. Both mold compound and leadframe metal are cut in the dicing process.